Four Sinn Fein politicians have received a telephone death threat from a caller police have traced to southern Spain, the party has said.

The menacing warning that Stormont Assembly member Paul Butler and three of his colleagues in Lisburn council would be shot imminently was apparently made from a phone box in Cadiz, near Gibraltar, the MLA said.

Police would not comment on the incident - stating that it was not policy to give out details on individual security cases.

But Mr Butler claimed officers have privately told the party they had traced the threat - which was made to councillor Angela Nelson's home - to Spain.

The caller said Ms Nelson, Mr Butler and councillors Charlene O'Hara and Arder Carson would all be assassinated.

"I have been told by the PSNI that they are taking the threat seriously," said Mr Butler.

"We believe it is no coincidence that these threats have been made ahead of a Lagan Valley Sinn Fein selection convention (for the General Election) in Lisburn next week.

"I want to say that Sinn Fein will not be deterred by these threats.

"Our project to achieve equality, work for Irish unity, and do our best for our constituents will continue."

A police spokeswoman said: "We do not discuss the security of individuals. However, if we receive information that a person's life may be at risk we will inform them accordingly. We never ignore anything which may put an individual at risk."